DRILLING ROCK BIT Russian patent published in 2013 - IPC E21B10/18 

FIELD: oil and gas industry.

SUBSTANCE: bit comprises legs with mills installed on them and channels for scrubbing agent supply, where check valves are installed, comprising a protective vessel with a seat, a stop valve and a return spring. The check valve is equipped with a flexible thin-walled bushing connected with the vessel capable of axial displacement and having an outer surface, which is congruous to the working surface of the seat and installed with it concentrically. At the same time the protective vessel of the bushing is arranged with a seat for the upper part of the bushing.

EFFECT: higher efficiency of rock bit operation as a result of improvement of reliability of check valve operation and its sealing.

2 cl, 2 dwg